A Long Term Evolution (LTE) network is widely applied because the LTE network supports relatively high bandwidth and has a relatively strong anti-interference capability. Referring to FIG. 1, FIG. 1 is a schematic diagram of a system architecture of an existing LTE network. As shown in FIG. 1, the LTE network mainly includes an evolved universal terrestrial radio access network (E-UTRAN) 110 and a core network (CN) 120. The E-UTRAN mainly includes an evolved base station, which is also referred to as an evolved NodeB (eNB) 111. The core network 120 mainly includes a mobility management entity (MME) 121, a serving gateway (S-GW) 122, a policy and charging rules function (PCRF) entity 123, a packet data network gateway (P-GW) 124, and the like. User equipment (UE) accesses a wireless network via the eNB in, and establishes a connection to an external network, for example, the Internet, via the core network.
In an E-UTRAN protocol architecture, a control plane (also referred to as a signaling plane) and a user plane (also referred to as a data plane) are separated. That is, control plane data and user plane data between the eNB 111 and the core network are processed by using different network elements. The user plane data is transmitted between the eNB 111 and the S-GW 122 in the core network 120, and an interface between the eNB in and the S-GW 122 is defined as an S1 user plane interface (S1-U interface). The control plane data is transmitted between the eNB 111 and the MME 121, and an interface between the eNB in and the MME 121 is defined as an S1 control plane interface (S1-MME interface). When the UE has a service, a user plane bearer is established by using the control plane, and after the bearer is successfully established, the user plane data may be transmitted by using the bearer.
At present, when a control plane connection is interrupted, that is, a connection between the eNB and the MME is interrupted, the eNB immediately releases a control plane resource and a user plane resource, resulting in a user service interruption, and affecting user experience.